Pressure responsive cross-over valve apparatus



Oct. 4, 1966 o. N. OLIVER 3,276,523

PRESSURE RESPONSIVE CROSS-OVER VALVE APPARATUS Filed Dec. 11, 1965 2 Sheets-Sheet l INVENTOR.

OWEN N. OLlVER BY M $0M, M @uhr/M A TTOR NE Y6 o. N. OLIVER 3,276,523

PRESSURE RESPONSIVE CROSSOVER VALVE APPARATUS 2 Sheets-Sheet 2 TOR.

OWEN N. OLIVER A TTOR N E Y6 United States Patent M 3,276,523 PRESSURE RESPGNSIVE CROSS-OVER VALVE APFARATUfl Owen N. Oliver, Duncan, Gilda, assignor to Hailihurton Company, Duncan, Okla, a corporation of Delaware Filed Dec. 11, 1963, Ser. No. 329,668 7 Claims. ((11. 166-184) This invention pertains to an apparatus for selectively allowing fluid flow through wall portions of conduit means in a well bore. It relates in particular to a unique cross-over valve structure which permits the simultaneous injection of well-treating fluids through a manifolded, tubing and easing annulus.

In well-treating operations, such as formation fractur ing, it is frequently desirable to first direct high pressurefracturing fluid to a formation through a tubing string to effect the initial formation breakdown or fracturing. Thereafter, in order to provide an adequate volume of fracturing fluid at the formation site, fracturing fluid bodies may be flowed both through the tubing and through the casing annulus and manifolded or joined within the tubing above conventional packer means which isolate the fracture zone.

While the technique described above is well known, the mechanisms heretofore provided for manifolding or comingling fluid bodies passing through the tubing and the casing annulus have been characterized by structural and/ or operational disadvantages. Such mechanisms have entailed a valve structure which required a mechanical manipulation to effect the opening and closing of the valve. Such mechanically manipulated valve arrangements have been found to be unduly complex and often unreliable in their operation. Indeed, in certain instances, it has been found impossible to effect the proper operation of such valves.

Recognizing the need for an improved valve structure which would enable the comingling of separately pumped fluid bodies moving through separate, concentric zones within a well bore, it is an object of this invention to provide such a valve arrangement which effectively obviates or minimizes disadvantages of previously used structures.

It is a particular object of the invention to provide such a structure which enables the joining or comingling of fluid bodies flowing through a well tubing and a casing annulus solely in response to a pressure differential existing between these fluid bodies.

It is a further object of the invention to provide such a pressure-responsive valve arrangement which is characterized by optimum structural simplicity and ease of installation and maximum operational reliability.

A still further object of the invention is to provide such a valve which may be conveniently and readily installed in conventional well-tubing strings without the necessity of effecting radical modifications to the string.

The apparatus presented through this invention for accomplishing the foregoing objectives includes conduit means adapted to be positioned within a well bore and spaced from well wall means. Port means are carried by the conduit means and extend through wall portions of this conduit means. These port means are adapted to provide fluid communication between the interior of the conduit means and an annular space between the conduit means and well wall means. It will be understood, of course, that in the ordinary installation the conduit means may comprise a tubing string while the annular space will comprise the space between the outer periphery of the tubing string and the inner periphery of the well, often defined by well casing.

Closure means are carried by the conduit means which are adapted to close the port means. The closure means 3,276,523 Patented Oct. 4, 1966 are adapted to open the port means in response to a fluid pressure differential existing between a fluid body contained within the conduit means and a fluid body contained within the aforesaid annular space.

The preferred embodiment of the invention by means of which optimum advantages of the invention are achieved is characterized by closure means comprising an annular collar and a plurality of flexible finger means. The annular collar is joined to the interior of the conduit means. The flexible finger means, which are joined to the collar and circumferentially spaced about conduit means interior, extend generally longitudinally from the collar toward the port means. The finger means include port closing portions which extend over and lie adjacent the port means.

In describing the preferred embodiment of the invention, reference will be made to the appended. drawings.

In the drawings:

FIGURE 1 is a schematic, partially sectioned, elevational view of the apparatus installed in a well bore with the port means closed by the closure means;

FIGURE 2 is a schematic, sectioned, elevational view of the FIGURE 1 apparatus showing the closure means displaced from the port means to allow the comingling or manifolding of fluid bodies passing through the tubing string and the casing annulus;

FIGURE 3 is an enlarged, sectional, and elevational view of a portion of the closure means shown in FIG- URE 1;

FIGURE 4 is a transverse, sectional view of the collar portion of the closure means of the FIGURE 1 apparatus as viewed along the section line 4-4 of FIGURE 2;

FIGURE 5 is a transverse, sectional view of an intermediate portion of the closure means of the FIGURE 1 apparatus as viewed along the section line 5-5 of FIG- URE 2;

FIGURE 6 is a transverse, sectional view of the port closing portions of the closure means of the FIGURE 1 apparatus as viewed along the section line 6-6 of FIG- URE 1;

FIGURE 7 is an enlarged, perspective and partially sectioned view of the closure means incorporated in the FIGURE 1 apparatus;

FIGURE 8 is an enlarged, perspective and partially sectioned view of an alternative form of the closure means shown in FIGURE 7; and

FIGURE 9 is a transverse sectional view of the port closing portions of the FIGURE 8 closure means embodiment as viewed along a section line corresponding to section 6-6 of the embodiment shown in FIGURES 1 through 7.

FIGURE 1 schematically illustrates a portion of a well bore 1 above a formation zone to .be fractured. In a conventional fashion, the well bore portion In above an exposed formation zone lb to be fractured, may be case-d by a conventional casing string 2 secured by cement 3.

A portion of a conduit string 4 used in a fracturing operation is shown in FIGURES 1 and 2. The portion of the tubing string 4 there shown comprises a conventional tubing section 5, a cross-over or comingling valve unit 6, and a tubing section 7. As shown, tubing section 5 may be threadably secured to the upper end of the valve unit 6, while the tubing section 7 may be threadably secured to the lower end of this valve unit.

A lower portion 3 of tubing string 4 may carry a conventional packer 9, schematically illustrated, which is adapted to isolate the fracturing zone 1b from the upper portion 1a of the well bore above the packer 9..

Valve unit 6 comprises a valve body which may be composite in character and defined by threadably interconnected and generally tubular sections 10, 11, and 12.

the annular space 24.

3 These tubular sections, in essence, define a conduit interconnection extending between tubular sections 5 and 7.

Intermediate valve body section 11 may include a plurality of symmetrically arranged, circumferentially spaced, and longitudinally elongated ports 13, which extend entirely through the side wall of body section 11. A closure assembly 14 may be mounted upon the interior of intermediate body section 11.

Closure assembly 14 includes a collar portion 15, the opposite ends of which are engaged and secured by annular abutments 16 and 17, formed respectively on body sections and 11 as shown.

Closure assembly 14 includes a plurality of valving finger means 18, which are spaced circumferentially and preferably symmetrically about the collar 15. Each finger means 18 is rigidly connected to the collar portion 15 and extends generally longitudinally of the tubing string and downwardly from the collar portion 15 toward a port 13. As shown in FIGURES 1 and 6, each such finger means 18 includes a port-closing portion 19 which extends across and lies adjacent to a port 13. In the relaxed position of each finger means 18, the port-closing portion 19 of that finger will lie adjacent to its associated port 13, so as to close, or substantially seal, the port.

Each finger means 18 is resilient in character so as to be capable of flexing inwardly toward the axis of the conduit string 4.

On the outer periphery of the valve body 6, an annular lip 20 may be carried. Lip 21 may be secured between annular abutments 20 and 22 formed on valve body sections 11 and 12.

Annular lip 20 extends outwardly from the outer periphery of the body of valve unit 6, which, it will be recalled, may be considered as a portion of the conduit string 4, and is configured such that its outer end 23 will wipingly engage the inner periphery of the well wall as defined by the casing string 2.

Annular lip 20 is sufliciently flexible that it may flex downwardly in response to the application of fluid pressure against the upper surface of the lip. Such flexing would ordinarily be prevented by the presence of well bore fluids below the lip.

The lip 20, in being somewhat larger in diameter than the inner diameter of the casing 2, will tend to assume the conical form shown in FIGURE 1 with the outer periphery of the lip in wiping engagement with the casing wall. With the lip thus positioned and supported from below by well fluids, it will serve as a freestanding barrier to tend to deflect fluid being pumped down the casing annulus 24 toward the ports 13.

The mode of operation of the apparatus illustrated in FIGURE 1 will now be described by reference to FIG- URES 1 and 2.

FIGURE 1 illustrates the fracturing string after it has been positioned within a well bore by conventional techniques. As Will be appreciated, under ordinary well bore conditions, the annular space 24 between the tubing string 4 and the casing string 2 would be filled with well fluids such that fluid would occupy the annular space 24a between the lip 22 and the packer 9.

With the tool positioned as shown in FIGURE 1, high pressure, well-treating fluids, such as fracturing fluid, may be pumped down the interior 25 of the tubing string 4- so as to flow into the fracture zone 1b. With this high pressure created in the interior tubing space 25, the port closing finger means 18 will be pressed firmly against the inner wall of the valve body section 11, so as to effectively close and seal the ports 13.

After the initial fracturing of the formation has been effected, such that it becomes desirable to inject fairly large quantities of fluid into the fracture zone 1b, additional treating fluids may be pumped downwardly through By adjusting the pressure of the fluid bodies being pumped through the tubing interior 25 and the casing annulus 24, a fluid pressure in the annular space 24 may be created which exceeds the pressure of the fluid flowing through the tubing interior 25 in the vicinity of the tubing string ports 13. By obtaining such a pressure differential, suflicient to overcome the normal resilience of the valving finger means 18, the finger means 18 may be caused to flex inwardly toward the central axis of the tubing string 4, as shown in FIGURE 2. This finger means flexing will uncover the ports 13 and allow fluid to flow from the annular space 24 into the interior 25 of the tubing string 4 and comingle with the fluid being pumped downwardly through the space 25. The thus manifolded or comingled fluid bodies will then flow downwardly to the lower portion of the fracturing string into the fracture zone 111.

While the comingling operation is taking place, the flexible lip 22 serves as a fluid deflector, as before noted and as a barrier to collect sediment such as sand, so as to prevent this sediment from falling downwardly and collecting on the top of the packer 8. As will be appreciated, this serves to minimize the possibility of sediment accumulating on the packer 8 to such an extent as to prevent its subsequent withdrawal.

As will be appreciated, the comingling of the fluid bodies passing to the tubular space 25 and the casing annulus 24 may be conveniently interrupted by merely reducing the pressure of fluid passing through the annular space 24. It should also be noted that, while fluid is passing into the fracturing zone only from the casing interior 25, difficulty may be encountered due to solids within this fluid body tending to deposit within the lower portion of the tubing string 4. In the event that this adverse condition should occur, by merely pumping fluid through the annular space 24 under high pressure, and making conventional well head adjustments to allow for an outflow of fluid from the top of the tubing string 4, a reverse circulation of fluid may be effected. This will allow a fluid flow downwardly through the annular space 24 and upwardly from the ports 13 through the tubing interior 25 to the Well head so as to clear the tubing interior.

Details of the specific configuration of the closure assembly 14, through which particular advantages of the invention are derived, are illustrated in FIGURES 3 through 9. Of these illustrations, FIGURES 3 through 7 are directed to the embodiment of the closure assembly 14, shown in FIGURE 1, While FIGURES 8 and 9 are directed to an alternative form of the closure assembly.

As shown in FIGURE 3, the collar portion 15 of the closure assembly 14 may be composite in character and include an inner, metallic collar or ring 26. As shown, ring 26 may be annular in character and have a generally rectangular cross section.

Each finger means 18 may also be composite in character and include an inner, metallic finger 27. As shown, each finger 27 may have a laterally elongate cross sectional configuration in its various portions and may be curved to generally conform to the configuration of the inner periphery of the body section 11. Each finger 27 may be fabricated from flexible or resilient metal so as to allow for the pressure-responsive flexing action heretofore described.

Metallic fingers 27 may comprise integral projections extending from ring 26 or may be separately fabricated fingers rigidly attached to the ring 26 by conventional fastening techniques such as welding.

An intermediate portion 28 of each metallic finger 27 may have a reduced thickness as shown in FIGURE 3. Thus, each portion 28 has a thickness less than the thickness of adjacent portions of the finger 27 lying both above and below the reduced portion 28. As shown in FIG- URE 7, in the portion of that figure which has been partially sectioned to show an exposed finger 27, the relatively thinned portion 28 may also lie in a reduced width portion of the finger 27 which extends between a portclosing portion 29 and the collar ring 26.

Each portion 28 of each finger 27, in having both a reduced width and reduced thickness, defines a flexing portion of the finger where the bending of the finger tends to be localized. Thus as shown in FIGURE 2, flexing of the finger means 18 in response to a fluid pressure differential will cause the metallic fingers 27 to bend in the flexing zones 28 rather than adjacent to the ports 13 or adjacent the junction of the fingers 27 with the ring 26. This avoids the creation of fatigue problems which would be associated with the flexing of the fingers 27 at their junctions with the ring 26 and further avoids the problems of incomplete port sealing and opening which might result by flexing of the fingers immediately opposite the ports 13.

As shown in FIGURES 3 and 7, each metallic finger 27, as well as the ring 26, may be coated with elastomeric material such as rubber, neoprene, or a synthetic plastic material. This coating protects the metallic components of the closure assembly 14 against abrasion and corrosion, and provides an improved seal between the port closing portion 19 of each finger means and the inner periphery of the conduit portion 11 immediately surrounding the port 13. The ring coating 30 and the finger coating 31 may be interconnected at the ring and finger junction as shown.

In order that the closure assembly 14 may be properly aligned so as to position the valve closing finger portions 19 in proper alignment with the ports 13, key means 32, illustrated in FIGURES 3 and 4, may be employed. Key means 32 may be positioned so as to extend between aligned slots 33 and 34 in the body section 11 and ring portion respectively or may be fabricated as an integral portion of either the valve body 11 or the collar portion 15.

FIGURES 8 and 9 illustrate an alternative embodiment of the closure assembly 14. In this alternative embodiment 14', the coating 31 of elastomeric material surrounding each metallic finger 27 has been extended between adjacent fingers so as to define a web 35 of elastomeric material extending between adjacent fingers. In this arrangement, a continuous sleeve of generally cylindrical configuration extends from the collar portion 15 and contains the embedded metallic fingers 27.

In describing the structural and functional aspects of the preferred tool embodiment, the advantages of the invention have been made apparent.

The cross-over valving concept, as described, enables comingling of Well fluids or reverse circulation to be achieved as often as desired and as rapidly as possible by merely controlling pump pressure at the well head.

The structural simplicity of the tool enables the fabrication and incorporation of the valve assembly in a conduit string with minimum cost and effort.

The operational reliability of the well tool is such as to assure the comingling of fluid bodies or the obtaining of reverse circulation with minimum manipulative effort and precisely when required so as to insure the success of welltreating operations.

The specific structure of the closure assembly, characterized by the abutment supported collar and the longitudinally extending valving fingers is especially significant. This structure enables the closure assembly to be easily installed. When installed the assembly provides virtually no interference with flow of fluid through the tubing or through the casing annulus. Although uniquely simple in structure, this closure assembly provides a significantly improved and reliable valving action in a well bore environment.

The elastomeric coating for the assembly in a unique, dually significant fashion, protects the assembly against corrosion and abrasion and provides an improved portclosing seal.

While the invention has been described with reference to preferred embodiments, it will be understood that it is not limited to the specific configuration, arrangements, or flow patterns herein described and illustrated. Modifications, additions, deletions, and substitutions with reference to the disclosed embodiment may be made Within the scope of the invention which is deemed to be defined in the appended claims.

I claim:

1. An apparatus for effecting the comingling of fluid bodies within a well bore, said apparatus comprising:

conduit means adapted to be positioned Within a well bore and spaced from well wall means;

port means carried by said conduit means, extending through side Wall portions of said conduit means, and adapted to provide fluid communication between the interior of said conduit means and an annular space between said conduit means and said Well wall means; and

closure means carried by said conduit means, said closure means being adapted to close said port means and being adapted to open said port means in response to a fluid pressure differential between a fluid body contained within said conduit means and a fluid body contained within said annular space;

said closure means comprising an annular collar secured to the interior of said conduit means and a plurality of flexible fingers joined to said collar, circumferentially spaced about said collar, and extending generally longitudinally from said collar toward said port means, said fingers including port-closing portions extending over and lying adjacent said port means.

2. An apparatus as described in claim 1 where each flexible finger is metallic and includes an intermediate, flexing portion between its port closing portion and said collar, with said intermediate portion having a Width and thickness less than the width and thickness of adjacent finger portions.

3. An apparatus as described in claim 1 wherein said flexible fingers are coated with elastomeric material.

4. An apparatus as described in claim 3 wherein said elastomeric material extends between adjacent fingers of said closure means so as to define a resilient web of elastomeric material connecting adjacent fingers.

5. An apparatus as described in claim 1 including axially spaced, first and second abutment means carried on the interior of said conduit means and engaging opposite ends of said collar.

6. An apparatus as described in claim 1 including an annular, flexible lip extending outwardly from the outer periphery of said conduit means and adapted to be positioned beneath but adjacent to said port means: when said conduit means is positioned within a well bore, said flexible lip being adapted to engage said well wall means.

7. An apparatus as described in claim 3 including axially spaced, first and second abutment means carried on the interior of said conduit means and engaging opposite ends of said collar, and further including an annular, flexible lip extending outwardly from the outer periphery of said conduit means and adapted to be positioned beneath but adjacent to said port means when said conduit means is positioned within a well bore, said flexible lip being adapted to engage said well wall means.

References Cited by the Examiner UNITED STATES PATENTS 2,716,454 8/1955 Abendroth 16642.1 2,944,794 7/1960 Myers 166-224 3,016,844 1/1962 Vincent 103233 CHARLES E. OCONNELL, Primary Examiner. J. A. LEPPINK, Assistant Examiner. 

1. AN APPARATUS FOR EFFECTING THE COMINGLING OF FLUID BODIES WITHIN A WELL BORE, SAID APPARATUS COMPRISING: CONDUIT MEANS ADAPTED TO BE POSITIONED WITHIN A WELL BORE AND SPACED FROM WELL WALL MEANS; PORT MEANS CARRIED BY SAID CONDUIT MEANS, EXTENDING THROUGH SIDE WALL PORTIONS OF SAID CONDUIT MEANS, AND ADAPTED TO PROVIDE FLUID COMMUNICATION BETWEEN THE INTERIOR OF SAID CONDUIT MEANS AND AN ANNULAR SPACE BETWEEN SAID CONDUIT MEANS AND SAID WELL WALL MEANS; AND CLOSURE MEANS CARRIED BY SAID CONDUIT MEANS, SAID CLOSURE MEANS BEING ADAPTED TO CLOSE SAID PORT MEANS AND BEING ADAPTED TO OPEN SAID PORT MEANS IN RESPONSE TO A FLUID PRESSURE DIFFERENTIAL BETWEEN A FLUID BODY CONTAINED WITHIN SAID CONDUIT MEANS AND A FLUID BODY CONTAINED WITHIN SAID ANNULAR SPACE; SAID CLOSURE MEANS COMPRISING AN ANNULAR COLLAR SECURED TO THE INTERIOR OF SAID CONDUIT MEANS AND A PLURALITY OF FLEXIBLE FINGERS JOINED TO SAID COLLAR, CIRCUMFERENTIALLY SPACED ABOUT SAID COLLAR, AND EXTENDING GENERALLY LONGITUDINALLY FROM SAID COLLAR TOWARD SAID PORT MEANS, SAID FINGERS INCLUDING PORT-CLOSING PORTIONS EXTENDING OVER AND LYING ADJACENT SAID PORT MEANS. 